Temporary bruising is the most common side effect of Botox. Headaches, which resolve in 24-48 hours, can occur, but this is rare. A small percentage of patients may develop eyelid drooping. This usually resolves in three weeks. This usually happens when the Botox moves around so you shouldn't rub the treated area for 12 hours after injection or lay down for three to four hours.

Study 2 compared 3 doses of BOTOX with placebo and included 91 patients [BOTOX 360 Units (N=21), BOTOX 180 Units (N=23), BOTOX 90 Units (N=21), and placebo (N=26)] with upper limb spasticity (expanded Ashworth score of at least 2 for elbow flexor tone and at least 3 for wrist flexor tone) who were at least 6 weeks post-stroke. BOTOX and placebo were injected with EMG guidance into the flexor digitorum profundus, flexor digitorum sublimis, flexor carpi radialis, flexor carpi ulnaris, and bic eps brachii (see Table 27).
In fertility studies of BOTOX (4, 8, or 16 Units/kg) in which either male or female rats were injected intramuscularly prior to mating and on the day of mating (3 doses, 2 weeks apart for males, 2 doses, 2 weeks apart for females) to untreated animals, reduced fertility was observed in males at the intermediate and high doses and in females at the high dose. The no -effect doses for reproductive toxicity (4 Units/kg in males, 8 Units/kg in females) are approximately equal to the maximum recommended human dose of 400 Units on a body weight basis (Units/kg).

Keep in mind that the price is often reflective of experience and quality. Botox injections gone wrong can lead to a  "Botox face", a droopy eyelid, migraine headaches, and frozen facial expressions. Unskilled or inexperienced injectors may also cause excessive bruising and more asymmetric results. Experienced plastic surgeons and dermatologists who are good Botox injectors can be much more expensive than injectors with limited experience.
In recent years, a number of high-profile lawsuits have been brought against Allergan in which plaintiffs claimed that off-label uses--for ailments including a child's cerebral-palsy symptoms, for instance, or an adult's hand tremors--resulted in lasting deleterious side effects. Still, the drug's acceptance in a growing number of doctors' offices worldwide, and its revenue growth, show no signs of slowing.
Headache is a universal experience. At present, there are more than 100 different types of headache and one of the most recurring ones is migraine, which affects approximately 10-12% of the population, being three times more common in women than in men. When migraine becomes chronic -occurring more than 15 days a month-, it can disrupt patients' daily life in a great degree.

Patients should shave underarms and abstain from use of over-the-counter deodorants or antiperspirants for 24 hours prior to the test. Patient should be resting comfortably without exercise, hot drinks for approximately 30 minutes prior to the test. Dry the underarm area and then immediately paint it with iodine solution. Allow the area to dry, then lightly sprinkle the area with starch powder. Gently blow off any excess starch powder. The hyperhidrotic area will develop a deep blue-black color over approximately 10 minutes.
Warnings and Precautions: In patients using LUMIGAN® (bimatoprost ophthalmic solution) or other prostaglandin analogs for the treatment of elevated intraocular pressure (IOP), the concomitant use of LATISSE® may interfere with the desired reduction in IOP. Patients using prostaglandin analogs including LUMIGAN® for IOP reduction should only use LATISSE® after consulting with their physician and should be monitored for changes to their intraocular pressure.
“A younger face has a heart shape, and an older face is a little more bottom-heavy and square,” says Dr. Matarasso. “But if you put toxin in both sides, you are not reducing the movement of the muscle, you are thinning the muscle out a bit. You can restore a youthful look. It’s not as dramatic or quick-acting as other areas, but it can be a nice way to improve the contour of the face.”
I tell my patients that it is not the total price that is important, but how many units are used. For instance, if a patient goes to a spa and pays $150 per area, that may sound like a great deal. However, when the patient ask how long the treatment is supposed to last, the spa responds "2 months". I have seen that many of those less expensive treatments often consist of around 10 units (and therefore carrying a "non-deal" $15 cost per unit!). So, what initially looks like a great bargain, is in fact just a treatment with an inadequate amount of Botox. Always ask your injector how many units they are using, so you can determine what price/unit you are getting. Experienced injectors know that there is no such thing as a standard amount of units, as everyone's facial anatomy and muscular strengths are variable, even from one side of the face to the other.
Above all, I try to be gentle with myself and my children. It’s easier said than done.  Mom guilt and migraine guilt weigh heavy on my heart, and I continue to remind myself that I’m doing my best. I give myself a break as I do with my children when they’re having a bad day. I’m patient with them and try to give myself the same respect.  As a mom, it seems like my job is never done and that I can always do better. The reality is, no one is perfect, and we all have our flaws. We don’t expect our children to be perfect, and we should not expect ourselves to be. We do what we can when we can and take each day as it comes. I find joy in the smallest things and find that being grateful and mindful remind me off all the blessings I have, despite my unpredictable and chronic migraine attacks.

The FDA now requires black box labeling on Botox and similar products such as Dysport and Xeomin to warn of rare but potentially life-threatening swallowing and breathing complications if the toxin spreads beyond the injection site. None of these complications have occurred in people using Botox for cosmetic reasons and the FDA states that cosmetic use of Botox appears to be safe.

Botulinum toxin exerts its effect by cleaving key proteins required for nerve activation. First, the toxin binds specifically to nerves which use the neurotransmitter acetylcholine. Once bound to the nerve terminal, the neuron takes up the toxin into a vesicle. As the vesicle moves farther into the cell, it acidifies, activating a portion of the toxin which triggers it to push across the vesicle membrane and into the cell cytoplasm.[1] Once inside the cytoplasm, the toxin cleaves SNARE proteins preventing the cell from releasing vesicles of neurotransmitter. This stops nerve signaling, leading to paralysis.[1]
In clinical trials, 30.6% of patients (33/108) who were not using clean intermittent catheterization (CIC) prior to injection, required catheterization for urinary retention following treatment with BOTOX® 200 Units as compared to 6.7% of patients (7/104) treated with placebo. The median duration of post-injection catheterization for these patients treated with BOTOX® 200 Units (n = 33) was 289 days (minimum 1 day to maximum 530 days) as compared to a median duration of 358 days (minimum 2 days to maximum 379 days) for patients receiving placebo (n = 7).